Edible oil detection method based on absorption spectrum and intelligent range hood

Abstract

The invention relates to an edible oil detection method based on an absorption spectrum and an intelligent range hood. The edible oil detection method comprises the following steps: acquiring the reference intensity of incident light and the actually measured intensity of the incident light after being transmitted through a target area; the target area is a gathering area of oil smoke airflow generated when edible oil is heated; the oil smoke airflow comprises a target substance generated by cracking of the edible oil; calculating the concentration value of the target substance based on the reference intensity and the actually measured intensity; calculating the current temperature value of the edible oil based on the concentration value and a preset oil temperature conversion model; according to the oil temperature conversion model, the corresponding relation between the target substance concentration and the edible oil temperature is calibrated, the non-contact temperature measurement effect is achieved, the problem that the non-contact oil temperature detection precision is low is solved, steam interference can be overcome, the oil fission condition can be directly monitored, and a high-precision detection result is obtained.

Description

Edible oil detection method based on absorption spectroscopy and intelligent range hood Technical Field

[0001] This application relates to the field of temperature detection technology, and in particular to a method for detecting edible oil based on absorption spectroscopy and an intelligent range hood. Background Technology

[0002] In Chinese cooking, controlling oil temperature is crucial for the quality and nutrient retention of dishes, and also significantly impacts the air quality of the cooking environment. If the oil temperature is too low, the ingredients easily absorb oil, resulting in a greasy taste; if the oil temperature is too high, it not only destroys the nutrients in the food but may also cause pyrolysis or oxidation of the oil, producing harmful substances such as acrolein and polycyclic aromatic hydrocarbons, along with a large amount of fumes that endanger human health and pollute the environment. Therefore, accurately controlling the oil temperature is a key step in achieving healthy and efficient cooking.

[0003] Currently, most common oil temperature monitoring methods on the market rely on insertion thermometers or infrared thermometers. However, the former requires direct contact with hot oil, posing a risk of cross-contamination and is inconvenient for cooking operations; while the latter, although non-contact, is easily affected by steam and oil fumes, resulting in unstable measurement accuracy.

[0004] There is currently no effective solution to the problem of low accuracy in non-contact oil temperature detection in related technologies. Summary of the Invention

[0005] This embodiment provides a method for detecting edible oil based on absorption spectroscopy and an intelligent range hood to solve the problem of low accuracy in non-contact oil temperature detection in related technologies.

[0006] In a first aspect, this embodiment provides a method for detecting edible oil based on absorption spectroscopy, the method comprising:

[0007] The reference intensity of the incident light and the measured intensity of the incident light after transmission through the target area are obtained; the target area is the area where the oil fume gas generated when the edible oil is heated is concentrated; the oil fume gas includes the target substances produced by the cracking of the edible oil;

[0008] Based on the reference intensity and the measured intensity, the concentration value of the target substance is calculated;

[0009] Based on the concentration value and the preset oil temperature conversion model, the current temperature value of the edible oil is calculated; the oil temperature conversion model calibrates the correspondence between the concentration of the target substance and the temperature of the edible oil.

[0010] In some embodiments, the concentration value of the target substance is calculated based on the reference intensity and the measured intensity, including:

[0011] The current absorbance of the target region is calculated based on the ratio of the reference intensity to the measured intensity.

[0012] The light absorption coefficient and optical path length of the target material are obtained, wherein the optical path length is the distance between the emitting module and the receiving module of the light source;

[0013] The concentration of the target substance is calculated based on the absorption coefficient, optical path length, and absorbance.

[0014] In some of these embodiments, the oil temperature conversion model satisfies the following formula:

[0015] T = k1 × ln(c) + k2;

[0016] Where T represents the temperature of the edible oil, c represents the concentration of the target substance, k1 represents the slope coefficient, and k2 represents the intercept coefficient.

[0017] In some embodiments, the method further includes:

[0018] When the concentration value is greater than a preset concentration threshold, a preset sampling interval value is obtained;

[0019] The effective time parameter is obtained by weighting the sampling interval value based on the current temperature value.

[0020] Update the cumulative time parameter based on the effective time parameter and the prior cumulative time parameter;

[0021] Based on the cumulative time parameter, the current oil deterioration index is determined.

[0022] In some embodiments, the method further includes:

[0023] If the oil deterioration index is greater than the preset deterioration threshold, an oil change reminder signal will be generated.

[0024] In some embodiments, the sampling interval value is weighted based on the current temperature value to obtain an effective time parameter, including:

[0025] The corresponding weighting coefficient is obtained based on the current temperature value; wherein, when the temperature value is less than the first temperature threshold, the corresponding weighting coefficient is set to zero; when the temperature value is greater than the first temperature threshold and less than the second temperature threshold, the corresponding weighting coefficient is set to a value greater than zero and less than 1; when the temperature value is greater than the second temperature threshold, the corresponding weighting coefficient is set to a value greater than 1.

[0026] The effective time parameter is obtained by multiplying the weighting coefficients and the sampling interval.

[0027] In some embodiments, the method further includes:

[0028] If the temperature value is greater than the preset first adjustment threshold and less than the second adjustment threshold, an instruction to increase the exhaust speed is generated.

[0029] If the temperature value is greater than the second adjustment threshold and less than the third adjustment threshold, a medium-speed exhaust command and an alarm command are generated.

[0030] If the temperature value is greater than the third adjustment threshold, a high-level exhaust command and a heat source shutdown command are generated.

[0031] In some of these embodiments, the target substance is acrolein; and the incident light is ultraviolet light.

[0032] Secondly, this embodiment provides an intelligent range hood, including: a transmitting module, a receiving module, and a control module;

[0033] The transmitting module and the receiving module are arranged opposite to each other on both sides of the target area;

[0034] The transmitting module is used to emit incident light toward the target area;

[0035] The receiving module is used to receive the transmitted light formed by the incident light passing through the target area and generate the corresponding measured intensity.

[0036] The control module is used to perform the steps of the method described in any one of the first aspects.

[0037] In some embodiments, the receiving module includes a narrowband filter and a photoelectric sensor;

[0038] The transmitting module is used to transmit incident light in the 200-400nm frequency band;

[0039] The narrowband filter is positioned opposite to the transmitting module and is used to filter the received transmitted light and emit a light signal with a center wavelength of 280nm.

[0040] The photoelectric sensor is positioned opposite the narrowband filter and is used to collect the measured intensity of the filtered light signal.

[0041] Thirdly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the edible oil detection method based on absorption spectroscopy described in the first aspect.

[0042] Compared with related technologies, the edible oil detection method and intelligent range hood based on absorption spectroscopy provided in this embodiment obtain the reference intensity of incident light and the measured intensity of the incident light after transmission through the target area; the target area is the area where the oil fume gas flow generated when edible oil is heated gathers; the oil fume gas flow includes the target substance produced by the cracking of edible oil; the concentration value of the target substance is calculated based on the reference intensity and the measured intensity; the current temperature value of the edible oil is calculated based on the concentration value and a preset oil temperature conversion model; the oil temperature conversion model calibrates the correspondence between the concentration of the target substance and the temperature of the edible oil, realizes the non-contact temperature measurement effect, and solves the problem of low accuracy of non-contact oil temperature detection. It can overcome steam interference, directly monitor the cracking of oil, and obtain high-precision detection results.

[0043] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0044] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0045] Figure 1 is a schematic diagram of the relative installation of the smart range hood and the stove in an embodiment of this application;

[0046] Figure 2 is a schematic diagram of the working principle of the intelligent range hood in the embodiment of this application;

[0047] Figure 3 is a schematic diagram of the transmitting module and the receiving module being installed relative to each other in the air duct of the smart range hood in an embodiment of this application;

[0048] Figure 4 is a flowchart illustrating the edible oil detection method based on absorption spectroscopy in an embodiment of this application.

[0049] Figure 5 is a flowchart illustrating an edible oil detection method based on absorption spectroscopy in another embodiment of this application;

[0050] Figure 6 is a schematic diagram of the intelligent control process based on oil temperature in a preferred embodiment of this application;

[0051] Figure 7 is a schematic diagram of the detection process for the degree of aging of edible oil in a preferred embodiment of this application.

[0052] Reference numerals: 100, intelligent range hood; 110, transmitting module; 120, receiving module; 121, narrowband filter; 122, photoelectric sensor; 130, control module; 140, fan; 200, cooktop. Detailed Implementation

[0053] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0054] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these” used in this application do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to these processes, methods, products, or devices. Words such as “connected,” “linked,” and “coupled” used in this application are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. Normally, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," "third," etc., used in this application are merely to distinguish similar objects and do not represent a specific order of objects.

[0055] This embodiment provides a method for detecting edible oil based on absorption spectroscopy. This method is used at least to detect the current temperature of the edible oil, and can further detect the degree of aging based on the current temperature. The current temperature or degree of aging can also be used to further intelligently control the heating heat source (the heat source heating the edible oil) or the flue gas emission (the device for treating the oil fume airflow generated when heating the edible oil). This method is applicable to scenarios such as smart kitchens and experimental testing. In the application scenario of a smart kitchen, as shown in Figures 1 and 2, the smart range hood 100 includes: a transmitting module 110, a receiving module 120, and a control module 130. As shown in Figure 3, the transmitting module 110 and the receiving module 120 are installed opposite each other in the air duct of the smart range hood 100. Especially when the smart range hood 100 is working, a large amount of oil fume airflow will pass through the air duct, that is, between the transmitting module 110 and the receiving module 120. The red arrow in Figure 3 indicates the direction of the incident light. The transmitting module 110 is used to emit incident light into the oil fume airflow in the air duct. The receiving module 120 includes a narrowband filter 121 and a photoelectric sensor 122. The narrowband filter 121 is positioned opposite to the transmitting module 110 and is used to filter the received transmitted light. The photoelectric sensor 122 is positioned opposite to the narrowband filter 121 and is used to collect the measured intensity corresponding to the filtered light signal. Based on the measured intensity collected by the intelligent range hood 100, an edible oil detection method based on absorption spectroscopy can be implemented.

[0056] Figure 4 is a flowchart of the edible oil detection method based on absorption spectroscopy in this embodiment. As shown in Figure 4, the process includes the following steps:

[0057] Step S210: Obtain the reference intensity of the incident light and the measured intensity of the incident light after transmission through the target area; the target area is the area where the oil fume gas generated when the edible oil is heated gathers; the oil fume gas includes the target substances generated by the cracking of edible oil.

[0058] Specifically, the wavelength of the light source is selected based on the target substance. For example, if the target substance is acrolein produced by the cracking of edible oil, and acrolein has major absorption peaks in both the ultraviolet and infrared bands, then ultraviolet or infrared light can be selected as the incident light. Since the human body, fire, and lighting sources all radiate infrared light, ultraviolet light is preferred in scenarios with many interfering sources. After selecting the light source, the corresponding reference intensity is measured in an environment without oil fume or airflow.

[0059] Step S220: Calculate the concentration value of the target substance based on the reference intensity and the measured intensity.

[0060] Specifically, based on the reference intensity and the measured intensity, the relationship between light intensity attenuation and gas concentration is analyzed, which can eliminate systematic errors such as light source fluctuations and optical component attenuation.

[0061] Step S230: Based on the concentration value and the preset oil temperature conversion model, the current temperature value of the edible oil is calculated; the oil temperature conversion model calibrates the correspondence between the concentration of the target substance and the temperature of the edible oil.

[0062] Specifically, the concentration of the target substance usually increases with the rise of oil temperature. Based on this, the oil temperature conversion model can be calibrated, and the real-time oil temperature can be deduced.

[0063] In this embodiment, the reference intensity of the incident light and the measured intensity of the incident light after transmission through the target area are obtained; the target area is the area where the oil fume gas generated when the edible oil is heated gathers; the oil fume gas includes the target substance produced by the cracking of the edible oil; the concentration value of the target substance is calculated based on the reference intensity and the measured intensity; the current temperature value of the edible oil is calculated based on the concentration value and the preset oil temperature conversion model; the oil temperature conversion model calibrates the correspondence between the concentration of the target substance and the temperature of the edible oil, solves the problem of low accuracy of non-contact oil temperature detection, and can overcome steam interference, directly monitor the cracking of oil, and obtain high-precision temperature detection results.

[0064] In some embodiments, step S220 above, which calculates the concentration value of the target substance based on the reference intensity and the measured intensity, specifically includes the following steps:

[0065] Step S221: Calculate the current absorbance of the target area based on the ratio of the reference intensity to the measured intensity.

[0066] Step S222: Obtain the light absorption coefficient and optical path length of the target material. The optical path length is the distance between the emitting module and the receiving module of the light source.

[0067] Step S223: Calculate the concentration of the target substance based on the absorption coefficient, optical path length, and absorbance.

[0068] Specifically, based on the Lambert-Beer Law, the following calculation formula is constructed:

[0069] ;

[0070] Where A represents the absorbance, I0 represents the reference intensity, I represents the measured intensity, ε represents the absorption coefficient of the target substance, c represents the concentration of the target substance, and L represents the optical path length. The absorption coefficient can be pre-calibrated experimentally, and the optical path length is obtained based on the sensor installation position.

[0071] In this embodiment, based on Beer-Lambert's law, the relationship between light intensity attenuation and gas concentration and path length is used to improve the accuracy of the concentration value of the target substance.

[0072] In some of these embodiments, the oil temperature conversion model satisfies the following formula:

[0073] T = k1 × ln(c) + k2;

[0074] Where T represents the temperature of the edible oil, c represents the concentration of the target substance, k1 represents the slope coefficient, and k2 represents the intercept coefficient.

[0075] Specifically, different types of edible oils are tested and calibrated in advance. For example, the temperature of soybean oil and the corresponding concentration of the target substance are measured and fitted with a formula to obtain the specific values ​​of the slope coefficient and intercept coefficient.

[0076] In this embodiment, the logarithmic term of the oil temperature conversion model is better suited to the nonlinear characteristics of physical processes such as light absorption and scattering, thereby improving the detection sensitivity in low-concentration regions.

[0077] In some embodiments, referring to Figure 5, the edible oil detection method based on absorption spectroscopy further includes:

[0078] Step S240: When the concentration value is greater than the preset concentration threshold, obtain the preset sampling interval value.

[0079] Step S250: The sampling interval value is weighted based on the current temperature value to obtain the effective time parameter.

[0080] Step S260: Update the cumulative time parameter based on the valid time parameter and the prior cumulative time parameter.

[0081] Step S270: Determine the current oil deterioration index based on the cumulative time parameter.

[0082] Specifically, repeated high-temperature heating of edible oil produces harmful substances such as acrolein and polar compounds. Traditional methods require manual observation of oil color changes or the use of special test strips, which cannot quantify the degree of oil deterioration in real time. In this embodiment, the cumulative time parameter can be directly used as the Oil Deterioration Index (ODI), calculated as follows:

[0083] ;

[0084] Wherein, α(T) i ) represents the temperature weighting coefficient, Δt i This represents the sampling interval value. In other embodiments, the cumulative time parameter can be combined with the conversion coefficient to calculate the corresponding oil deterioration index. The specific implementation method is not limited in this embodiment.

[0085] Specifically, after step S240, the method further includes: when the concentration value is less than a preset concentration threshold, the prior accumulated time parameter is used as the current oil deterioration index, or the prior accumulated time parameter is combined with a conversion coefficient to calculate the corresponding oil deterioration index. In other words, when the concentration value is less than the preset concentration threshold, the time is not accumulated.

[0086] In this embodiment, based on the calculation of the target substance concentration and oil temperature, real-time detection of the degree of oil deterioration is realized. The effective time under high concentration conditions is accumulated based on a preset concentration threshold, and a weighted algorithm based on oil temperature range is used to avoid misjudgment of short-term high temperature, which is more in line with the actual deterioration law of oil and improves the accuracy of judgment.

[0087] In some embodiments, step S250 above, which involves weighting the sampling interval values ​​based on the current temperature value to obtain the effective time parameter, specifically includes the following process:

[0088] Step S251: Obtain the corresponding weighting coefficient based on the current temperature value; wherein, when the temperature value is less than the first temperature threshold, the corresponding weighting coefficient is set to zero; when the temperature value is greater than the first temperature threshold and less than the second temperature threshold, the corresponding weighting coefficient is set to a value greater than zero and less than 1; when the temperature value is greater than the second temperature threshold, the corresponding weighting coefficient is set to a value greater than 1.

[0089] Step S252: Based on the product of the weighting coefficient and the sampling interval, the effective time parameter is obtained.

[0090] Specifically, the time information for assessing oil aging is correlated with temperature in a tiered manner. For example, the first temperature threshold is set to 160℃ and the second temperature threshold is set to 190℃. If the current temperature value T < 160℃, the weighting coefficient is 0; if 160 ≤ T < 190℃, the weighting coefficient is 0.8; and if T ≥ 190℃, the weighting coefficient is 1.2.

[0091] In this embodiment, the weighting coefficient for temperatures below the first temperature threshold is forced to be 0 to eliminate interference from unstable low-temperature data. Edible oil decomposes faster at high temperatures, which has a significant impact on quality. By increasing the weighting coefficient for high temperatures, accuracy is enhanced, and through hierarchical correlation, it is better adapted to the actual deterioration pattern of oil products.

[0092] In some embodiments, the method further includes step S280: if the oil deterioration index is greater than a preset deterioration threshold, an oil change reminder signal is generated. For example, when the cumulative effective high-temperature duration (oil deterioration index) exceeds, for example, 1 hour, an oil change reminder is triggered.

[0093] In this embodiment, the degradation of cooking oil quality can be detected in a timely manner, triggering an alert promptly. This effectively mitigates the health risks associated with repeatedly using oil during cooking.

[0094] In some embodiments, the edible oil detection method based on absorption spectroscopy further includes:

[0095] Step S310: If the temperature value is greater than a preset first adjustment threshold and less than a second adjustment threshold, a ventilation level increase command is generated. The ventilation level increase command is used to increase the airflow level of the range hood; preferably, the ventilation level increase command indicates an increase of 1 level.

[0096] In step S320, if the temperature value is greater than the second adjustment threshold and less than the third adjustment threshold, a medium-range exhaust command and an alarm command are generated. The medium-range exhaust command adjusts the range hood's airflow to the middle setting, preventing insufficient airflow from affecting fume treatment efficiency and excessive airflow from increasing unnecessary power consumption. The alarm command drives the indicator light to flash or displays an alarm interface on the screen.

[0097] In step S330, if the temperature value is greater than the third adjustment threshold, a high-level exhaust command and a heat source shutdown command are generated. The high-level exhaust command instructs the range hood to adjust its fan speed to the highest level, and the heat source shutdown command controls the stove to turn off the power or the heat source switch.

[0098] In this embodiment, the range hood and stove are controlled by multi-level early warning linkage, which realizes accurate dry burning warning and automatic smoke exhaust control.

[0099] This embodiment also provides a smart range hood. Referring to Figure 2, the smart range hood includes: a transmitting module 110, a receiving module 120, and a control module 130; the transmitting module 110 and the receiving module 120 are arranged opposite to each other on both sides of the target area; the transmitting module 110 is used to transmit incident light into the target area; the receiving module 120 is used to receive the transmitted light formed by the incident light passing through the target area and generate the corresponding measured intensity; the control module 130 is used to execute the steps of the method in any of the above embodiments.

[0100] Specifically, the smart range hood also includes a fan 140, and a control module 130 is connected to the fan 140; the control module 130 can also be connected to the cooktop 200 to control the fan 140 or the cooktop 200 based on the detection results of the cooking oil temperature or the oil deterioration index.

[0101] In this embodiment, the reference intensity of the incident light and the measured intensity of the incident light after transmission through the target area are obtained; the target area is the area where the oil fume gas generated when the cooking oil is heated gathers; the oil fume gas includes the target substance produced by the cracking of the cooking oil; the concentration value of the target substance is calculated based on the reference intensity and the measured intensity; the current temperature value of the cooking oil is calculated based on the concentration value and the preset oil temperature conversion model; the oil temperature conversion model calibrates the correspondence between the concentration of the target substance and the temperature of the cooking oil, realizing a non-contact temperature measurement effect, improving cooking safety, and solving the problem of low oil temperature detection accuracy in non-contact cooking. It can overcome steam interference, directly monitor the cracking of oil, and obtain high-precision detection results.

[0102] In some embodiments, referring to FIG2, the receiving module 120 includes a narrowband filter 121 and a photoelectric sensor 122. The transmitting module 110 is used to transmit incident light in the 200-400nm frequency band.

[0103] Narrowband filter 121 is disposed opposite to the transmitting module 110 and is used to filter the received transmitted light and emit an optical signal with a center wavelength of 280nm. Specifically, the center wavelength of narrowband filter 121 is 280nm±5nm and the bandwidth is 10nm.

[0104] A photoelectric sensor 122 is positioned opposite to a narrowband filter 121 to collect the measured intensity of the filtered light signal. Specifically, a silicon photodiode (response wavelength 200-1100nm) is used.

[0105] In this embodiment, the concentration of acrolein produced by the cracking of edible oil was calculated by measuring the light intensity attenuation in the 280nm band.

[0106] The present embodiment will now be described and illustrated through preferred embodiments.

[0107] Referring to Figures 1 and 2, the intelligent range hood 100 in this preferred embodiment includes: a transmitting module 110, a receiving module 120, and a control module 130. As shown in Figure 3, the transmitting module 110 and the receiving module 120 are installed opposite each other within the air duct of the intelligent range hood 100. Especially when the intelligent range hood 100 is working, a large amount of oil fume airflow passes through the air duct, i.e., between the transmitting module 110 and the receiving module 120. The red arrow in Figure 3 indicates the direction of incident light. The transmitting module 110 is used to emit incident light in the 200-400nm frequency band (with a focus on covering the 280nm band) into the oil fume airflow in the air duct. The receiving module 120 includes a narrowband filter 121 and a photoelectric sensor 122; the narrowband filter 121 has a center wavelength of 280nm±5nm and a bandwidth of 10nm, and is arranged opposite to the transmitting module 110 to filter the received transmitted light. The photoelectric sensor 122, which uses a silicon photodiode (response wavelength 200-1100nm), is positioned opposite to the narrowband filter 121 and is used to collect the measured intensity corresponding to the filtered light signal.

[0108] Control module 130 is used to execute the steps of the edible oil detection method based on absorption spectroscopy, as shown in Figures 6 and 7. The method specifically includes the following steps:

[0109] S1. After the system starts, the control emission module 110 is turned on to preheat the light source. After preheating, the reference light intensity of the incident light is corrected to obtain the reference intensity I0 of the incident light.

[0110] S2, obtain the measured intensity I of the incident light after it passes through the target area; the target area is the area through which the oil fume airflow passes in the air duct of the smart range hood 100; the oil fume airflow includes the target substance produced by the cracking of edible oil: acrolein.

[0111] S3, based on the ratio of the reference intensity to the measured intensity, calculate the current absorbance of the target area A=log 10 (I0 / I).

[0112] S4. Obtain the absorption coefficient ε and optical path length L of the target substance, where L is the distance between the emitting module 110 and the receiving module 120 of the light source. Based on the absorption coefficient ε, optical path length L, and absorbance A, calculate the concentration value of the target substance c = A / (εL). The calibrated absorption coefficient of acrolein is 15.6 L·mol⁻¹. -1 ·cm -1 The optical path length was measured to be 10 cm.

[0113] S5, based on the concentration value c and a preset oil-temperature conversion model, calculates the current temperature T of the edible oil; the oil-temperature conversion model calibrates the correspondence between the target substance concentration and the edible oil temperature. The oil-temperature conversion model satisfies the following formula:

[0114] T = k1 × ln(c) + k2;

[0115] Where T represents the temperature of the edible oil, c represents the concentration of the target substance, k1 represents the slope coefficient (with a value of 18.2), and k2 represents the intercept coefficient (with a value of 152.3).

[0116] S6, if the temperature value T is greater than the preset first adjustment threshold of 180℃ and less than the second adjustment threshold of 210℃, a command to increase the exhaust level is generated; the command to increase the exhaust level is used to control the fan 140 of the smart range hood 100 to increase the airflow by 1 level. If the temperature value T is less than the preset first adjustment threshold of 180℃, the fan 140 of the smart range hood 100 is controlled to maintain the current level.

[0117] S7. If the temperature value T is greater than the second adjustment threshold of 210℃ and less than the third adjustment threshold of 250℃, a medium-range exhaust command and an alarm command are generated. The medium-range exhaust command is used to control the fan 140 of the smart range hood 100 to increase the airflow to the medium level. The alarm command is used to instruct the smart range hood 100 to activate the audible and visual alarm. If the temperature value T is less than the second adjustment threshold, the process returns to S2 to continue measurement.

[0118] S8: If the temperature value is greater than the third adjustment threshold of 250℃, a high-level exhaust command and a heat source shutdown command are generated. The high-level exhaust command controls the intelligent range hood 100 to adjust the fan speed of the fan 140 to the highest level, and the heat source shutdown command controls the stove 200 to turn off the power or the heat source switch. If the temperature value is less than the third adjustment threshold, the process returns to S2 to continue measurement.

[0119] S9, when the concentration value is greater than the preset concentration threshold, obtain the preset sampling interval value Δt; calculate the effective time parameter Δt based on the current temperature value T, and obtain the effective time parameter Δt_1; update the cumulative time parameter t_sum = t_sum + Δt_1 based on the effective time parameter Δt_1 and the prior cumulative time parameter t_sum; determine the current oil deterioration index (ODI) based on the updated cumulative time parameter t_sum. Wherein, when the temperature value is less than the first temperature threshold, the corresponding weighting coefficient is set to zero; when the temperature value is greater than the first temperature threshold and less than the second temperature threshold, the corresponding weighting coefficient is set to 0.8; when the temperature value is greater than the second temperature threshold, the corresponding weighting coefficient is set to 1.2.

[0120] S10. If the oil deterioration index is greater than the preset deterioration threshold (1 hour), an oil change reminder signal will be generated.

[0121] In this preferred embodiment, by installing an ultraviolet spectral sensor inside the range hood duct, the intensity of the characteristic absorption peak of acrolein (a product of edible oil cracking) at a wavelength of 280nm is detected in real time. Based on Lambert-Beer's law and an oil temperature conversion model, the oil temperature is calculated, enabling non-contact three-level oil temperature early warning and linkage control (180℃ / 210℃ / 250℃). This solves the problems of traditional solutions being unable to penetrate steam interference and directly monitor oil cracking, achieving precise dry-burning early warning and automatic smoke exhaust control. This preferred embodiment also assesses the degree of oil aging by accumulating the duration of high-concentration acrolein concentration, combined with an oil temperature range weighted algorithm, thus addressing the health hazards of repeated oil use.

[0122] It should be noted that the steps shown in the above process or in the flowchart of the accompanying figures can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0123] Furthermore, in conjunction with the edible oil detection method based on absorption spectroscopy provided in the above embodiments, this embodiment can also provide a storage medium. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the edible oil detection methods based on absorption spectroscopy in the above embodiments.

[0124] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0125] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0126] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0127] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method for detecting edible oils based on absorption spectroscopy, characterized in that, The method includes: acquiring a reference intensity of incident light and a measured intensity of the incident light after transmission through a target area; the target area is a region where oil fume gas generated during the heating of edible oil accumulates; the oil fume gas includes target substances produced by the cracking of edible oil; calculating the concentration value of the target substance based on the reference intensity and the measured intensity; calculating the current temperature value of the edible oil based on the concentration value and a preset oil temperature conversion model; the oil temperature conversion model calibrates the correspondence between the concentration of the target substance and the temperature of the edible oil.

2. The method for detecting edible oil based on absorption spectroscopy according to claim 1, characterized in that, The concentration value of the target substance is calculated based on the reference intensity and the measured intensity, including: calculating the current absorbance of the target region based on the ratio of the reference intensity and the measured intensity; obtaining the absorption coefficient and optical path length of the target substance, wherein the optical path length is the distance between the emitting module and the receiving module of the light source; and calculating the concentration value of the target substance based on the absorption coefficient, the optical path length, and the absorbance.

3. The method for detecting edible oil based on absorption spectroscopy according to claim 1, characterized in that, The oil temperature conversion model satisfies the following formula: T=k1×ln(c)+k2; where T represents the oil temperature, c represents the target substance concentration, k1 represents the slope coefficient, and k2 represents the intercept coefficient.

4. The method for detecting edible oil based on absorption spectroscopy according to claim 1, characterized in that, The method further includes: when the concentration value is greater than a preset concentration threshold, obtaining a preset sampling interval value; performing a weighted calculation on the sampling interval value based on the current temperature value to obtain an effective time parameter; updating the cumulative time parameter based on the effective time parameter and the prior cumulative time parameter; and determining the current oil deterioration index based on the cumulative time parameter.

5. The method for detecting edible oil based on absorption spectroscopy according to claim 4, characterized in that, The method further includes generating an oil change reminder signal if the oil deterioration index is greater than a preset deterioration threshold.

6. The method for detecting edible oil based on absorption spectroscopy according to claim 4, characterized in that, The effective time parameter is obtained by weighting the sampling interval value based on the current temperature value, including: obtaining the corresponding weighting coefficient based on the current temperature value; wherein, when the temperature value is less than a first temperature threshold, the corresponding weighting coefficient is set to zero; when the temperature value is greater than the first temperature threshold and less than a second temperature threshold, the corresponding weighting coefficient is set to a value greater than zero and less than 1; when the temperature value is greater than the second temperature threshold, the corresponding weighting coefficient is set to a value greater than 1; and the effective time parameter is obtained by multiplying the weighting coefficient and the sampling interval.

7. The method for detecting edible oil based on absorption spectroscopy according to claim 1, characterized in that, The method further includes: if the temperature value is greater than a preset first adjustment threshold and less than a second adjustment threshold, generating an exhaust level increase command; if the temperature value is greater than the second adjustment threshold and less than a third adjustment threshold, generating a medium-speed exhaust command and an alarm command; if the temperature value is greater than the third adjustment threshold, generating a high-speed exhaust command and a heat source shutdown command.

8. The method for detecting edible oil based on absorption spectroscopy according to claim 1, characterized in that, The target substance is acrolein; the incident light is ultraviolet light.

9. A smart range hood, characterized in that, include: The system includes a transmitting module, a receiving module, and a control module; the transmitting module and the receiving module are arranged opposite to each other on both sides of the target area. The transmitting module is used to transmit incident light into the target area; the receiving module is used to receive the transmitted light formed by the incident light passing through the target area and generate the corresponding measured intensity. The control module is used to execute the steps of the method according to any one of claims 1 to 8.

10. The intelligent range hood according to claim 9, characterized in that, The receiving module includes a narrowband filter and a photoelectric sensor; the transmitting module is used to transmit incident light in the 200-400nm frequency band; the narrowband filter is disposed opposite to the transmitting module and is used to filter the received transmitted light and emit an optical signal with a center wavelength of 280nm; the photoelectric sensor is disposed opposite to the narrowband filter and is used to collect the measured intensity corresponding to the filtered optical signal.

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